Restore Your Truck’s Brain and Get Back on the Road
Is your reliable 1998-1999 Chevrolet 2500 Pickup suddenly giving you headaches? If you’re dealing with frustrating issues like a persistent Check Engine Light, erratic engine performance, or even a no-start condition, the problem often lies with a failing Powertrain Control Module (PCM). As the central computer of your truck, a faulty PCM can cause a cascade of problems that are difficult to diagnose. This isn’t just an inconvenience; it affects your truck’s reliability, fuel economy, and emissions.
This is a dependable, tested, and pre-programmed replacement PCM that serves as a direct-fit solution. We take a genuine, used OEM unit and flash it with the latest official GM software updates, specifically matched to your truck’s Vehicle Identification Number (VIN). This means you get a part that’s not just a replacement but is loaded with the most current operational data from the manufacturer for optimal performance. Forget expensive dealership visits for programming—this 1998-1999 Chevrolet 2500 PCM arrives at your door ready for installation.
From the Diagnostic Bay: The Ghost in the Machine
I remember a customer with a ’99 Suburban who was at his wit’s end. He’d replaced the fuel pump, spark plugs, and even the distributor trying to solve an intermittent stalling issue. The truck would run fine for days, then die at a stoplight without warning. No consistent codes were stored, just a generic P0300 (Random Misfire) now and then. After checking fuel pressure and spark, which were perfect, we hooked up a scope to the injector drivers at the PCM. We saw the injector pulse signal simply drop out randomly. The culprit was a failing driver inside the original PCM. We installed a VIN-programmed unit just like this one, and the truck has run flawlessly ever since. It’s a classic example of how a failing 1998-1999 Chevrolet 2500 PCM can mimic other component failures.
Is Your Truck Showing These Symptoms?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, it’s a strong indicator that your engine computer may need replacement:
- ✔ Check Engine Light is on with codes like P0601, P0602, or P0606 (Internal Control Module Errors).
- ✔ Engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine stalls, stumbles, or misfires intermittently.
- ✔ Failure to communicate with a diagnostic scan tool.
A Straightforward Guide to Installation
Installing your replacement PCM is a manageable job for a DIY enthusiast. Following these steps will help ensure a smooth process. Remember, your new module is pre-programmed, but a security relearn procedure may be necessary.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most 1998-1999 Chevy/GMC trucks, the PCM is located in the engine compartment, typically on the driver’s side fender well.
- Disconnect the Connectors: Carefully unclip and remove the electrical wiring harnesses from the old PCM. These connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Old Unit: Unbolt the old PCM from its mounting bracket. Keep the hardware, as you may need it for the new unit.
- Install the New PCM: Mount the replacement PCM onto the bracket and securely reconnect the wiring harnesses. You should hear a ‘click’ as they lock into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn (if needed): Your vehicle’s anti-theft system (PassLock/VATS) may need to be synchronized with the new PCM. A common procedure is to turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeat this cycle three times. Afterwards, the vehicle should start.
Verified Vehicle Compatibility
While this is the correct 1998-1999 Chevrolet 2500 PCM, this versatile module, identified by service number 09355699, fits a wide range of GM trucks, vans, and SUVs from that era. Please cross-reference your original part number with our list (09355699, 16266645, 16250279, 16258815, 09366810) and check the fitment data below to confirm it’s the right part for your specific vehicle and engine.
CHEVROLET 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
CHEVROLET 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
GMC 1500 PICKUP 98-99 Electronic Control Module; gasoline (LH engine compartment), ID 9355699
GMC 2500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
GMC 3500 PICKUP 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
TAHOE/YUKON 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
SUBURBAN 1500/2500 98-99 Electronic Control Module; gasoline (LH front engine compartment), ID 9355699
ESCALADE 99 Electronic Control Module; (LH front engine compartment), ID 9355699
EXPRESS/SAVANA VAN 1500/2500/3500 98-99 Electronic Control Module; gasoline, ID 9355699
ASTRO/SAFARI VAN 98 Electronic Control Module; (LH front by battery), ID 9355699
BLAZER S10/JIMMY S15 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 9355699
S10/S15/SONOMA 98 Electronic Control Module; 6-262 (4.3L), w/o build date opt ZN4; ID 9355699
BRAVADA 98 Electronic Control Module; (6-262, 4.3L), w/o build date opt ZN4; ID 9355699
ENVOY 98 Electronic Control Module; (RH front engine compartment), w/o build date opt ZN4; ID 9355699
ISUZU HOMBRE 98 Electronic Control Module; 4.3L (6 cylinder), w/o extended build date opt ZN4; ID 9355699
Frequently Asked Questions
Do I need to do anything after I purchase?
Yes. After you place your order, you must provide us with your vehicle’s 17-digit VIN. We cannot program and ship the module without it. This ensures the PCM is a perfect match for your vehicle’s factory specifications.
Is this part difficult to install?
Installation is generally straightforward for someone with basic mechanical skills. It involves disconnecting the battery, unplugging the old module, swapping it with the new one, and reconnecting everything. The most critical step afterward is the security relearn procedure, which does not require special tools.
What does “flashed with the newest updates” mean?
Manufacturers often release software updates for PCMs to fix bugs, improve transmission shifting, and enhance engine efficiency. We program your module with the latest stable software version released by GM for your specific vehicle, ensuring you get the best possible performance.
Will I need to have a CASE relearn performed?
For many of these GM vehicles, a Crankshaft Variation (CASE) relearn is recommended after PCM replacement to prevent a P1336 trouble code. While the truck will run without it, this procedure requires a bi-directional scan tool and is best performed by a professional mechanic to optimize engine timing and misfire detection.
Is this a used part?
Yes, this is a genuine OEM computer sourced from a salvaged vehicle. Each unit is thoroughly inspected and tested before being programmed to your VIN to ensure reliability and proper function.